ARDMS SPI STUDY GUIDE
COMPLETELY SOLVED TOP GRADE A+
In soft tissue, if the frequency of a wave is increased the Propagation Speed (PS) will... correct
answerRemain the Same because stiffness and density affect Propagation Speed.
What is the audible range? correct answer20-20,000Hz
>20,000Hz=Ultrasound
Frequency is measured in correct answerHertz (Hz)
is
Cycles per Second
Not affected by sonographer
Increase Frequency; Decrease Depth
A period is the length of time it takes for correct answerone complete wavelength to pass a fixed point
PRP is determined by correct answerTransmit time and receive time.
Period is measured in correct answerTime (μs)
When the sonographer changes the imaging depth what parameters are changed? correct answerPRP,
PRF, Duty Factor
,What is duty factor? correct answerThe percentage or fraction of time that the system is transmitting a
pulse (Time Sound is ON or ON-Time).
Propagation Speed in SOFT TISSUE correct answer1.54 mm/μs
(1540 m/sec)
Unit of measurement for Pulse Duration, Duty Factor, PRP, and Period correct answerTime, (μs)
Pulse duration is determined by correct answerSound Source Only
Pulse Duration is controlled by correct answerthe ultrasound system and transducer
Pulse Duration Formula correct answerpulse duration (μs) = # cycles in pulse/frequency(MHz)
PD= Number of cycles in Pulse/ Frequency(Hz)
Spatial Pulse Length (SPL) (measurement) correct answerThe distance that a pulse occupies in space
from the start to the end of a pulse.
(mm)
Typical values for spatial pulse length in soft tissue. correct answer0.1 to 1.0 mm
Spatial pulse length is determined by correct answersound source and medium
Spatial Pulse Length is directly proportional to correct answerthe Number of Cycles in the Pulse
and
the Wavelength
(Directly Proportional means that increased SPL will increase both the number of cycles in the pulse and
the wavelength if increased).
, Spatial pulse length is inversely proportional to correct answerFrequency (MHz)
(Inversely Proportional means that increased SPL will lower frequency. This is because axial resolution is
better with lower frequency)
Pulse Duration (PD) correct answerThe actual time from the start of a pulse to the end of that pulse; a
single transmit, talking, or "on" time.
Time the pulse is on typically measured in (ms).
Pulse Length correct answerThe distance of the pulse start to end or the
duration or length of a single pulse
Pulse Length is typically measured in (mm).
the ability of an object to resist compression and relates to the hardness of a medium? correct
answerStiffness.
Think:
↑ Stiffness ↑ Speed
↓ Density ↑ Speed
An increase in pulse repetition frequency would lead to: correct answerIncreasing pulse repetition
frequency, increases duty factor.
↑ PRF ↑ Duty Factor
Which of the following would have the highest propagation speed? correct answerBone has the highest
propagation speed, at 2000-4000 m/s.
What has the lowest propagation speed? correct answerair technically has the lowest propagation
speed at 300 m/s
COMPLETELY SOLVED TOP GRADE A+
In soft tissue, if the frequency of a wave is increased the Propagation Speed (PS) will... correct
answerRemain the Same because stiffness and density affect Propagation Speed.
What is the audible range? correct answer20-20,000Hz
>20,000Hz=Ultrasound
Frequency is measured in correct answerHertz (Hz)
is
Cycles per Second
Not affected by sonographer
Increase Frequency; Decrease Depth
A period is the length of time it takes for correct answerone complete wavelength to pass a fixed point
PRP is determined by correct answerTransmit time and receive time.
Period is measured in correct answerTime (μs)
When the sonographer changes the imaging depth what parameters are changed? correct answerPRP,
PRF, Duty Factor
,What is duty factor? correct answerThe percentage or fraction of time that the system is transmitting a
pulse (Time Sound is ON or ON-Time).
Propagation Speed in SOFT TISSUE correct answer1.54 mm/μs
(1540 m/sec)
Unit of measurement for Pulse Duration, Duty Factor, PRP, and Period correct answerTime, (μs)
Pulse duration is determined by correct answerSound Source Only
Pulse Duration is controlled by correct answerthe ultrasound system and transducer
Pulse Duration Formula correct answerpulse duration (μs) = # cycles in pulse/frequency(MHz)
PD= Number of cycles in Pulse/ Frequency(Hz)
Spatial Pulse Length (SPL) (measurement) correct answerThe distance that a pulse occupies in space
from the start to the end of a pulse.
(mm)
Typical values for spatial pulse length in soft tissue. correct answer0.1 to 1.0 mm
Spatial pulse length is determined by correct answersound source and medium
Spatial Pulse Length is directly proportional to correct answerthe Number of Cycles in the Pulse
and
the Wavelength
(Directly Proportional means that increased SPL will increase both the number of cycles in the pulse and
the wavelength if increased).
, Spatial pulse length is inversely proportional to correct answerFrequency (MHz)
(Inversely Proportional means that increased SPL will lower frequency. This is because axial resolution is
better with lower frequency)
Pulse Duration (PD) correct answerThe actual time from the start of a pulse to the end of that pulse; a
single transmit, talking, or "on" time.
Time the pulse is on typically measured in (ms).
Pulse Length correct answerThe distance of the pulse start to end or the
duration or length of a single pulse
Pulse Length is typically measured in (mm).
the ability of an object to resist compression and relates to the hardness of a medium? correct
answerStiffness.
Think:
↑ Stiffness ↑ Speed
↓ Density ↑ Speed
An increase in pulse repetition frequency would lead to: correct answerIncreasing pulse repetition
frequency, increases duty factor.
↑ PRF ↑ Duty Factor
Which of the following would have the highest propagation speed? correct answerBone has the highest
propagation speed, at 2000-4000 m/s.
What has the lowest propagation speed? correct answerair technically has the lowest propagation
speed at 300 m/s
